Question

I’ve been using the BitmapImage.DownloadProgress event to wait until the image is loaded when creating a bitmap from a URI. That was I can use an event handler to check the Image.ActualWidth/ActualHeight after the download is complete. This works fine.

But when I am loading an image that the user has selected from their computer, the DownloadProgress is useless.

This works for URI bitmaps:

private void LoadImage(Uri uri) {     this.ResetProgressImage();     BitmapImage image = new BitmapImage();                 image.DownloadProgress += new EventHandler<DownloadProgressEventArgs>(LoadImageDownloadProgress);     image.UriSource = uri;     this.ImageFull.Source = image; }  private void LoadImageDownloadProgress(object sender, DownloadProgressEventArgs e) {     this.Dispatcher.BeginInvoke(delegate     {         this.ProgressImage.Value = e.Progress;         if (e.Progress == 100)         {             ImageHelper.Current.Width = Math.Round(this.ImageFull.ActualWidth);             ImageHelper.Current.Height = Math.Round(this.ImageFull.ActualHeight);         }     }); } 

But this doesn’t work when getting a BitmapImage from a stream:

private void LoadImage(Stream stream) {     this.ResetProgressImage();     BitmapImage image = new BitmapImage();                 image.DownloadProgress += new EventHandler<DownloadProgressEventArgs>(LoadImageDownloadProgress);                 image.SetSource(stream);     this.ImageFull.Source = image; } 

Does anyone know an alternative to DownloadProgress, when using SetSource(stream)?

Answer 1

There is no event in BitmapImage to monitor the loading progress using a stream.

However, if you just need the image dimensions, you can add the image to the hierarchy and wait for the ‘Loaded’ or ‘LayoutUpdated’ event.